1. Field of the Invention
The present invention relates to an electronic casing and a method of manufacturing the same. More particularly, the present invention relates to a method of manufacturing an electronic casing that enables the electronic casing to have desirable surface quality and an electronic casing manufactured thereby.
2. Description of the Related Art
With the rapid progress of our times and the rapid development of electronic products, more and more people carry with one or more portable electronic product, such as cell phone, PDA, or walkman. In the prior art, in order to improve the portability, the electronic products are developed to become lighter, thinner and smaller. Moreover, in order to reduce the weight, casings of the electronic products are often made of plastic such as polymer with a light weight.
However, plastic casings made of polymer are not as good as the metal products in terms of appearance and strength. Since plastic casings are neither shock-resistant nor abrasion-resistant, after being used for a long time, the casings of the products will suffer damage from shocks or abrasions, and the structural strength of the casings will also be weak.
FIG. 1 shows a casing structure of a conventional electronic product. As shown in FIG. 1, the casing of an electronic product at least includes a reflective layer 11 and a composite layer 12. The composite layer 12 is formed by polymers with particles 13 mixed therein. Then, metals such as aluminum, nickel, iron, copper or cobalt-chromium alloy are plated on the composite layer 12 through sputtering or electroplating, so as to form the reflective layer 11.
Though metal materials are plated on the plastic casing through sputtering or electroplating to improve the appearance of the casing, the strength of the casing is not improved significantly. Accordingly, some manufacturers make improvements by manufacturing casings entirely with metal materials.
However, conventional metal casings are often made of a single metal material, such as titanium-based material, stainless steel or aluminum-based material, among which aluminum-based material is the most commonly used. However, the added value of aluminum-based material is rather low. Titanium-based material has excellent surface quality as well as higher specific strength. However, titanium-based material has a strong springback after the common stamping process, such it is difficult to control the forming precision of the casings. While a hydraulic forming process, which has better forming forces, can be adopted to solve this problem, it is too slow for high-speed mass production. In addition, titanium-based material is poor electrical conductive, so an electromagnetic forming process cannot be used thereon. Therefore, it is difficult to manufacture casings with titanium-based material. As to stainless steel, it is relatively heavy, and, for similar reasons, the forming precision of stainless steel is also not desirable.
FIGS. 2A and 2B show a conventional forming process of electronic products. As shown in FIG. 2A, a metal casing 21 is formed by a stamping process in advance, so as to form a pre-formed body. A bending portion with a greater radius of curvature is formed at a turning portion 24, so in the reprocessing, as shown in FIG. 2B, one profiler 23 is disposed on each side of the turning portion 24 of the metal casing 21 (pre-formed body), and thus, the casing of an electronic product with better precision is formed by forging or stamping process 22. However, the forging or stamping process 22 often leaves scratches on the surface of the metal casing 21, which in turn affects the usefulness of the casing made of metal materials.
Therefore, it is necessary to provide an electronic casing and a manufacturing method thereof to solve the above problems.